The effect of general vs spinal anesthesia on the inflammatory response in orthopedic surgery Adresa pentru corespondenþã: Tamas A. Szabo, MD, PhD Department of Anesthesiology Room E 212, Ralph H. Johnson Veterans Affairs Medical Center 109 Bee Street Charleston, South Carolina 29401 E-mail: tamas.szabo@va.gov Jurnalul Român de Anestezie Terapie Intensivã 2012 Vol.19 Nr.1, 13-20 The effect of general vs spinal anesthesia on the inflammatory response in orthopedic surgery T.A. Szabo 1 , R.D. Warters 1 , B. Kadry 1 , R.E. Stroud 2 , R.G. Matthews 2 , S.M. DeSantis 3 , F.G. Spinale 2 1 Department of Anesthesia and Perioperative Medicine, Medical University of South Carolina, Charleston, South Carolina 2 Division of Cardiothoracic Surgery and Anesthesia, Medical University of South Carolina, Charleston, South Carolina 3 Department of Medicine, Medical University of South Carolina, Charleston, South Carolina Abstract Background: Cytokines are regulatory peptides that respond to inflammatory challenges and provide communication between cells during stress. An exaggerated perioperative inflammatory response is associated with poor clinical outcomes. This study tested the hypothesis that a differential profile of cytokine release would occur in patients undergoing orthopedic surgery under general anesthesia vs spinal anesthesia. Methods: Thirty patients undergoing total knee arthroplasty (TKA) were divided in two groups, general anesthesia (GA, n = 15) and spinal anesthesia (SP, n = 15). Blood samples for interleukin-1â (IL-1â), IL-6 and TNFá were drawn at baseline and 6, 12, 24, and 48 hours after incision. The plasma was subjected to enzyme linked multiplex suspension array in order to measure representative cytokines. Results: There was a significant anesthetic effect on each cytokine. Spinal anesthesia resulted in higher IL-6 (p = 0.018), higher TNFá (p < 0.001), and lower IL-1â levels (p = 0.014). There was a two- fold higher increase of IL-6 in the SP group compared to the GA group. TNFá levels decreased in the GA group. Conclusions: These findings demonstrate that a differential profile of cytokine release occurs in TKA patients receiving different types of anesthesia. SP elicits a greater inflammatory response than GA as indicated by significantly increased IL-6 and TNFá levels. Since the inflammatory response contributes to overall morbidity, this differential cytokine profile may have significant implications for patients undergoing TKA with pre-existing co-morbidities or increased operative risk. Key words: orthopedic surgery, cytokines, general anesthesia, spinal anesthesia J Rom Anest Terap Int 2012; 19: 13-20 Introduction Cytokines belong to a diverse group of regulatory polypeptides that act locally to respond to inflammatory or ischemic challenges and provide communication between cells during stress [1, 2]. The plasma cytokine response to surgery and trauma involves a complex release of both proinflammatory and antiinflammatory cytokines. Cytokines are cha- racterized by tight gene control, short duration of action and an autocrine or paracrine mode of action, thus affecting only the immediate environment. The release of cytokines can be stimulated by a number of factors, including ischemia-reperfusion, complement activation, endotoxin-release and the effect of other cytokines. Prototypical inflammatory cytokines include interleukin- 6 (IL-6), IL-1 beta (IL-1â) and tumor necrosis factor alpha (TNFá). There appears to be a significant correlation be- tween the surgical trauma and the IL-6 response suggesting that the overall response is related to the magnitude of tissue damage [3]. Several studies have established that preemptive analgesia (e.g.: epidural blockade, lumbar plexus block with sciatic nerve block) plays an important role in the attenuation of the cytokine response, peripheral and central nervous system sensitization, and pain [4, 5]. Other studies have yielded equivocal results regarding the effect of the anesthetic regimen on the differential release of inflammatory cytokines [6-11].